import java.nio.file.*;
import java.util.*;

public class Euler81 {
    public static void main(String[] args) throws Exception {
        List<String> lines = Files.readAllLines(Path.of("resources/documents/0081_matrix.txt"));
        int n = lines.size();
        int[][] m = new int[n][n];
        for (int i = 0; i < n; i++) {
            String[] parts = lines.get(i).trim().split(",");
            for (int j = 0; j < n; j++)
                m[i][j] = Integer.parseInt(parts[j]);
        }
        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++) {
                if (i == 0 && j == 0)
                    continue;
                else if (i == 0)
                    m[i][j] += m[i][j - 1];
                else if (j == 0)
                    m[i][j] += m[i - 1][j];
                else
                    m[i][j] += Math.min(m[i - 1][j], m[i][j - 1]);
            }
        System.out.println(m[n - 1][n - 1]);
    }
}